My 2003 E500 has a subtle noise on acceleration that I would describe as a subtle "diesel-like" clatter, or "tapping noise". It's most pronounced on mild acceleration, and goes away on full throttle. I just bought this car this week and was wondering if this was a normal sound for this V8; although I've had other M-Bs with V8s, none of them have made this sound (32v 91 SL500 & 97 E420) Even after running 93 octane, the tapping noise has not diminished. Is this the sound of a normal 24-valve V8? The car runs very smoothly, with no vibration or hesitation, and feels very powerful too. Crude stopwatched 0-60 times are in the 5.7 second range, so performance is excellent. Any thoughts?

"Sounds like" classic pre-ignition, or engine knock. It shouldn't happen, particularly since you're using 93 octane. You might try a different brand of gasoline next time ... maybe a "brand" name, such as Shell or BP. Let us know how this works out. Good luck.

I have been experiencing the exact noise on my 03 E500. I had the car at mercedes dealership a few days ago for another problem and asked them about the noise. they drove the car with me and said the noise is related to engine mounts. Hard for me to accept. i thout it might be cat. converter. The car has 3 of them 2 in front. the part is about $400 and labor about $350. I have not fix it yet, but I will. My car has about 70,000. on it. Good luck.

well my car has a rattle when i close the drivers door and it also makes the same noise if the car is started and in park and i give it some gas it will make that noise so get it on a lift of get under it safely and tighten up the bo;ts.
i think there all 8mm.

I spent about $800 hoping to get rid of the tap tap noise but did not work. My car has about 70,000 miles and the old motor mount looked great, no damage at all. But replaced them anyway. The clatter noise, diesel noise or the tap tap continues. Any ideas? The noise is not a losse part. I have switched gas graded and brands, changed motor oil with no luck.

I spent about $800 hoping to get rid of the tap tap noise but did not work. My car has about 70,000 miles and the old motor mount looked great, no damage at all. But replaced them anyway. The clatter noise, diesel noise or the tap tap continues. Any ideas? The noise is not a losse part. I have switched gas graded and brands, changed motor oil with no luck.

If I remember correctly the motor mount is a gas charged mount. Mine failed and they "looked great" when removed. They had failed.